1. Technical Field
The present invention relates to a print control device, a print control method, and a print control program.
2. Related Art
A printer which discharges an ink from a nozzle for discharging an ink and performs a printing has been known. Such a printer discharges each ink such as black, cyan, magenta, yellow, and the like from each nozzle corresponding to respective inks. However, not every ink is always used in a printing, and monochrome printing is also performed where black ink only is used. In such a case, nozzles corresponding to inks other than a black ink are plugged by ink around the nozzles, which is dried and has increased viscosity since the frequency of use of the nozzle is low.
As a solution to the plugged nozzles, an image processing method that forms the image using a black ink and forms dots of the black ink and each color ink at the same position when an input image is in black has been known (refer to JP-A-2009-269321 and JP-A-2008-162258). In addition, an image forming apparatus has been known which has an ink usage adjustment unit adjusting the amount of use of the black ink and color inks and an image drawing unit drawing a monochrome image on a recording medium using the adjusted ink, and in which the ink usage adjustment unit adjusts the amount of use of each ink based on property of each ink to be used (drying characteristic of an ink) and a use environment (temperature, humidity, area, type of recording medium) so as not to get the nozzles plugged by drying of each ink (refer to JP-A-2010-184415).
As in each document described above, when a black ink and a color ink are used in printing a monochrome image, the influence of the color ink may cause an adverse effect that a density of black color of a printed result (referred to as an optical density (OD) value) is lower than a value originally expected and the printed result is in a gray color. In addition, as in JP-A-2009-269321 and JP-A-2008-162258 described above, a method of forming dots of color inks of different colors at the same position, when a positional deviation occurs between the dots to be formed at the same position due to transport accuracy of a print medium, positional accuracy of a print head and a nozzle, and the like, has blurring of an outline of the image and a hue deviation, thereby causing an image quality to be decreased.